Right now, it's like going up on a mountain on a unicycle-

現在，這就像騎著獨輪車上山，背著裝滿炸藥的背包……

with a backpack full of explosives.

...非常慢，

Incredibly slow, you can't transport a lot of stuff, and you might die.

你不能運送太多東西，否則可能會死亡。

A rocket needs to reach a velocity about 40,000km an hour to escape from Earth.

火箭需要以每小時約40,000公里的速度脫離地球

To get to that speed, rockets are mostly containers for fuel with a tiny tip of payload.

為了達到這樣的速度，火箭的大部分是燃料罐，只有一小部分是有效負載

This is bad if you want to go to other planets,

如果你想去其他星球可不容易，因為你需要很重的行李

because you need a lot of heavy stuff if you want to survive, and maybe even come back.

如果你想生存...甚至想要回來

So, is there a way to get to space with less fuel and more payload?

那麼，有沒有辦法以更少的燃料和更多的負載進入太空？

A nice thing that solved most of our transport problems on Earth is what you call infrastructure.

[開場音樂]

Whether it's roads for cars, ports for ships, or rails for trains,

解決地球上大多數運輸問題的一個辦法就是基礎設施

we've made it easier to get to places.

無論是汽車道路，輪船港口還是火車軌道

We can apply the same solution to space travel.

我們讓行程變得更加容易

Space infrastructure will make getting into orbit and out to the Moon, Mars, and beyond easier and cheaper.

我們可以將相同的解決方案應對太空旅行

Great, but what exactly is space infrastructure?

太空基礎設施將使進入軌道到達月球和火星更便宜和容易

Unlike an Earth space elevator, which is currently science fiction,

設想很好，但是太空基礎設施到底是什麼？

there is a simple yet promising technology that does not require new science,

與目前在科幻小說中的地球太空電梯不同

magic materials, or huge investments,

有一種簡單且更有希望的技術

and that has been tested successfully in orbit already.

不需要新的科學，魔法或巨額投資

A cable and a weight, known as a tether.

並且已經在軌道上成功測試

The concept is so simple; it's surprising.

電纜和重物，稱為繫繩

What if we put tethers,

這個概念是如此簡單，令人驚訝

hundreds or thousands of kilometers long — into space, and had spacecraft

如果我們將數百或數千公里長的繫繩放入太空，

use them as ladders to climb to higher altitudes and gain speed?

航天器是否能將它們用作梯子以達到更高的高度並獲得速度？

This concept is known as the Skyhook.

這個概念被稱為“天鈎”

It works even better if we make it spin.

如果我們旋轉它，它的效果甚至更好

A counterweight holds a long cable in place while it rotates around a circle.

負重繞圓旋轉時，將長電纜固定在適當的位置

A rotating tether slows down its tip relative to the ground at the bottom

相對於底部地面，旋轉的繫繩會降低其尖端的速度

and speeds it up at the top like a catapult.

並像彈射器一樣將其加速

This means that you can transfer energy from the tether

這意味著您可以從繫繩中轉換能量

and get a massive boost when released, more-or-less for free,

並在發射時獲得更大的提升

equal to twice the tether's rotation velocity.

大致的計算

Specialized fibers already exist that can survive the

等於繫繩旋轉速度的兩倍

extraordinary stresses a Skyhook would be faced with.

特種纖維已經存在，可以承受“天鈎”所需要的巨大壓力

To protect against cuts and collisions from debris and meteorites,

為了防止碎片和隕石的割傷和碰撞

we can thread our tether into a web of redundant fibres.

我們可以將繫繩穿入多層纖維網中

Since our Skyhook would pass over the same spot many times a day,

由於我們的天鉤一天要經過同一地點多次

this would allow small, reusable shuttles to catch up with it.

這使小型可重複利用的航天器可以趕上它

Of course, it's not that easy.

當然，這並不容易

At its lowest point, the tether's tip is dashing through

在最低點，繫繩的尖端以每小時約12,000公里的速度在大氣中飛馳

the atmosphere at around 12,000km/h.

由於地球的大氣，我們不能太多地降低天鉤

Because of Earth's atmosphere, we can't lower the Skyhook

否則由於空氣摩擦而發熱過大

too much or it will get too hot from air friction.

因此，它需要降到80至150公里的高度，並且不再更低

So it will dip to a height of 80 to

為了達到目的，我們需要可以抓到繫繩的專業航天器

150 kilometers and no lower.

雖然這並不容易，但它仍然比買一個大錫罐便宜得多

To match this, we'll need specialized spacecraft that can get to the tether.

裝滿火箭燃料，時速達到40,000公里

While this isn't exactly easy, it's still much cheaper than getting a big tin can, filled with rocket fuel, to go 40,000km/h.

捕捉尖端也將是一個挑戰

Catching the tip will be a challenge too.

只有短短60到90秒的時間去在天空中尋找以12馬赫（12倍音速）運動的微小物體

There's only a short time window of 60 to 90 seconds

為了簡化操作，尖端會有一條釣魚線

to find a tiny thing in the sky, moving at Mach 12.

一公里長，帶有幫助航天器連接的導航無人機

To make this easier, the tip could have a sort of fishing line a kilometer long

另一個挑戰是使我們的天鉤保持在軌道上

with a navigation drone that helps the spacecraft connect.

隨著越來越多的飛船挂在上面並向上拉

Another challenge is keeping our Skyhook in orbit.

儅它用盡了所有的動力來保持穩定

As more and more ships latch onto it and pull themselves up,

如果我們什麼都不做，它將減速並墜入大氣層

they use up the momentum that keeps it in place.

在這裡，我們可以稍微更改宇宙規律

If we don't do anything, it will slow down and crash into the atmosphere.

假設天鉤是一組軌道能量

And here, we can cheat the universe a bit.

可以平衡進出的有效負載

The Skyhook is a battery of orbital energy.

到達的飛船，將人類和物資帶回地球，為繫繩增加能量

It's possible to balance the payloads coming in and being sent off.

增加的能量可以給其他進入太空的船隻

Arriving ships bringing humans and materials home to earth add

這樣，繫繩不會損失任何能量。

energy to the tether, which it can give to other ships departing into space.

我們使用的越多，成本越低

This way, the tether doesn't lose any energy.

如果我們每次提升時仍在失去能量

The more we use it, the cheaper it gets.

我們可以用小型電動或化學發動機回收它

If we're still losing energy with each boost, we can recover it with small electric or chemical engines

定期糾正繫繩的位置

that regularly correct the tether's position.

一組繫繩，一個圍繞地球，一個圍繞火星，

A set of tethers, one around earth and one around Mars, could make trips

與火箭相比，可以使行星之間的旅行更快、更直接且成本更低

between the planets fast, straight-forward and low cost compared to rockets.

地球的繫繩將位於低地球軌道上，以捕獲人員和負載，並將其拉去火星

The Earth tether would sit in low earth orbit

火星的繫繩會抓住它們並放慢速度，使其平穩降落在地面

to grab people and payloads and fling them off to Mars.

在相反的方向上，繫繩可以捕捉到穿越火星稀薄大氣的運載工具

The Mars tether catches them and slows them down for a landing on the surface.

每小時僅約1000公里

In the opposite direction, the tether could pick up a vehicle travelling

不比我們在地球上的客機快多少

through Mars' thin atmosphere at only about 1,000km/h

然後將其扔回地球以捕獲並放下

not much faster than our airliners on Earth, and fling

繫繩可以將兩個星球之間的旅行時間從9個月縮短到5甚至3個

it back to Earth to be caught and lowered down.

並將所需火箭的規模減少84％至96％

The tethers could shorten trips between both planets,

更好的是，人們也許可以相對奢侈地旅行

from nine months down to five or even three,

因為我們有能力給乘客滿意的舒適度

and reduce the scale of the rockets required by between 84 and 96 percent.

繫繩旅行將是前往火星的頭等艙座位

Even better: people may be able to travel in relative luxury

同時，圍繞地球和火星的繫繩可以提供快速且經濟高效的運輸骨幹

as we could afford to invest in passenger comfort.

這將使太空旅行能被負擔得起

Tether travel would be first-class seats to Mars!

但是，讓我們走的更遠

Together, tethers around Earth and Mars could provide the

從低火星軌道開始，繫繩可以將飛船推向小行星帶

rapid and cost-efficient transportation backbone

送往新小行星的第一艘飛船將需要火箭以使其減速到達目的地

that would make space travel affordable.

隨後的到來者可能會找到一條繩索，等待著將其抓住並免費送回

But let's go further.

能否廉價地獲得小行星是開發太陽系資源的主要因素

Starting from low Mars orbit,

貴金屬和有價值的礦物可以被運送到火星

a tether could boost ships to the asteroid belt.

在它們從小行星上切下的幾週後

The first craft sent to a new asteroid

它們將變成我們行星際文明的完美基石

would need rockets to slow down at its destination.

但是，為什麼在這裡停下來？

Subsequent arrivals might find a tether waiting to

火星的衛星非常容易

catch them and send them back for free.

太陽系中沒有其他衛星靠近其運行

Getting to asteroids cheaply is a major factor

火衛一是如此的重，我們不必擔心它放慢速度

in opening up the resources of the solar system.

使其成為6,000公里以下超長繫繩的理想連接點

Precious metals and valuable minerals could be delivered to Mars

下端會飛過火星表面，很容易被抓住

just weeks after they were cut out of their asteroid.

頂端可以一路向木星和土星飛去

They would be the perfect building blocks for our interplanetary civilization.

相同的超級繫繩也可以拉近太陽系内部的距離

But why stop here?

金星和水星距離只有一步之遙

Mars moons are very convenient.

與火星不同，它們充滿了太陽能並且富含礦物質

No other moons in the solar system orbit that close to their planet.

從長遠來看，沒有什麼能阻止人類建設零推進劑運輸網絡

Phobos is so heavy that we don't need to worry about slowing it down,

以火星衛星為中心的陸地行星

making it the perfect attachment point for super-tethers

繫繩是使太空旅行能被負擔得起的相對便宜且可持續的解決方案

just under 6,000km long.

太陽系的其餘部分可供開采和探索

The lower tip would fly just over the surface of Mars and be very easy to catch.

考慮到我們現在就擁有可以構建它們的技術

The upper tip can fling ships all the way to Jupiter and Saturn.

確實沒有什麼好藉口再等

The same super-tether can also bring the inner solar system closer.

太陽系的某些部分距離很遠...

Venus and Mercury are a single swing away.

...但是它們可能非常接近

Unlike Mars, they're bursting with solar energy and are rich in minerals.

談一個難以達到但不一定必須達到的東西:

In the long term, nothing is stopping humanity from constructing a zero-propellent

知識

transport network for the terrestrial planets, centered on the Martian moons.

我們來自Brilliant的朋友可以帶您進入一個充滿爆炸性想法和有趣課程的世界

Tethers are a comparably cheap and sustainable solution to making space travel

Brilliant是一個網站，可幫助您以實用的方式解決科學問題

affordable and the rest of the solar system

提供互動式問題解決課程以及數學，邏輯和工程方面的日常問題

accessible for exploitation and exploration.

每個問題都為您提供了自己解決複雜主題所需的所有工具

Considering that we have the technology to build them today,

它是邊做邊學，但要用大腦而不是手

there's really no good excuse to wait any longer.

發揮好奇心，學到難題和課程的實質

Parts of the solar system are far away, but they could be very close.

關於諸如經典力學，天文學，引力物理學之類的東西

Speaking of stuff that is hard to reach, but doesn't have to be:

如果您點擊說明中的鏈接或訪問“ brilliant.org/nutshell”

Knowledge.

您可以免費註冊並學到比您想像更多的東西

Our friends from Brilliant can hook you up to a universe

而且，為Kurzgesagt觀眾提供了額外的優惠

full of explosive ideas and fun courses.

使用該鏈接的前688人獲得了年度會員資格的20％折扣

Brilliant is a website that helps you tackle science in a practical way,

這樣您就可以查看存檔中的所有日常問題並解鎖每門課程

with interactive problem-solving courses and

Brilliant將助您每日都更睿智一點

daily problems in maths, logic and engineering.

您可能會對體驗“贊不絕口”

Each problem gives you all the tools you need

[Outro音樂]

to crack complex topics all by yourself.

It's learning-by-doing, but with your brain instead of your hands.

Use your curiosity to get to the bottom of puzzles and courses about things like

classical mechanics, astronomy, gravitational physics and much more.

If you click the link in the description, or visit brilliant.org/nutshell,

you can sign up for free and learn more things than you can imagine.

And there's an extra perk for Kurzgesagt viewers:

The first 688 people to use the link get 20% off their annual membership,

which lets you view all the daily problems in the archives and unlock every course.

Brilliant helps you end your day a little smarter.

You might… get 'hooked' on the experience!